Japanese patent application publication No. 2005-058733A and Japanese patent application publication No. 2007-89650A discloses prior exercise assisting devices. The prior exercise assisting device is used by the user in a condition where the user sits on the seat for placing the buttocks on the seat and also the user places the user's feet on the foot support surfaces. When the seat is displaced, muscles of the femoral areas of the user is expanded and contracted while the user hardly bends the knee. In this exercise assisting device, a position of the seat is displaced for varying the ratio of the weight of the user which is supported by the seat, whereby the exercise assisting device varies the ratio of the weight of the user which acts on the legs of the user.
The prior exercise assisting device is configured to apply load lower than the total weight of the user to the user's legs. Furthermore, the prior exercise assisting device is configured to expand and contract the muscles of the femoral areas while the user hardly bends and stretches the user's knees. Therefore, persons having diabetes and also knee pains are able to use the exercise assisting device, whereby the persons having diabetes and also knee pains is able to enhance the muscles of the femoral areas. The femoral areas have large volumes. Therefore, when the user expands and contracts the muscles by using the exercise assisting device, the user is able to improve adult disease. Moreover, the exercise assisting device comprises the seat which is configured to be swung. Therefore, the user is passively exercised without using the muscles actively. Consequently, the user having low exercise capacity is able to exercise by the exercise assisting device. In addition, the user having low motivation for exercise is able to exercise by the exercise assisting device.
By the way, the prior exercise assisting device is configured to vary the user's weight acting on the user's legs to tighten and relax the muscles of the femoral areas while hardly bending and stretching the user's knee. Therefore, effective exercise depends on the bending angle which acts as a factor of tensing and relaxing the muscles of the femoral areas. As easily understood from the squat motion, the load applied to the femoral areas of the muscles is varied according to the bending angle of the knee. However, when the user having the knee pain bends the knees, the user having the knee pain feels pain in the knee of the user. Therefore, it is required for the exercise assisting device to restrict the bending angle of the knees of the user when the user having the knee pain uses the exercise assisting device.
In the present circumstances, it is thought that the suitable angle of the bending angle of the knee is determined as approximately 140 degrees. The 140 degrees of the suitable angle is based upon experimental results of the exercise effect which is maximized when the bending angles of the knees are approximately 140 degrees.
In addition, also according to the experimental result, the knee pain is minimized when the bending angle of the knees are approximately 140 degrees. It should be noted that the bending angle of the knee is defined by the angle made by the femoral area and the leg region in the front side of the knee.